83 lines
2.1 KiB
C
83 lines
2.1 KiB
C
|
/*=============================================================================
|
||
|
|
|
||
|
|
This file is part of FLINT.
|
||
|
|
|
||
|
|
FLINT is free software; you can redistribute it and/or modify
|
||
|
|
it under the terms of the GNU General Public License as published by
|
||
|
|
the Free Software Foundation; either version 2 of the License, or
|
||
|
|
(at your option) any later version.
|
||
|
|
|
||
|
|
FLINT is distributed in the hope that it will be useful,
|
||
|
|
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
||
|
|
GNU General Public License for more details.
|
||
|
|
|
||
|
|
You should have received a copy of the GNU General Public License
|
||
|
|
along with FLINT; if not, write to the Free Software
|
||
|
|
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
|
||
|
|
|
||
|
|
=============================================================================*/
|
||
|
|
/******************************************************************************
|
||
|
|
|
||
|
|
Copyright (C) 2011 Fredrik Johansson
|
||
|
|
|
||
|
|
******************************************************************************/
|
||
|
|
|
||
|
|
#include <gmp.h>
|
||
|
|
#include "flint.h"
|
||
|
|
#include "nmod_vec.h"
|
||
|
|
#include "nmod_poly.h"
|
||
|
|
#include "nmod_poly_mat.h"
|
||
|
|
|
||
|
|
void
|
||
|
|
nmod_poly_mat_det_interpolate(nmod_poly_t det, const nmod_poly_mat_t A)
|
||
|
|
{
|
||
|
|
slong i, l, n, len;
|
||
|
|
|
||
|
|
nmod_mat_t X;
|
||
|
|
mp_ptr x, d;
|
||
|
|
|
||
|
|
n = A->r;
|
||
|
|
|
||
|
|
if (n == 0)
|
||
|
|
{
|
||
|
|
nmod_poly_one(det);
|
||
|
|
return;
|
||
|
|
}
|
||
|
|
|
||
|
|
l = nmod_poly_mat_max_length(A);
|
||
|
|
|
||
|
|
if (l == 0)
|
||
|
|
{
|
||
|
|
nmod_poly_zero(det);
|
||
|
|
return;
|
||
|
|
}
|
||
|
|
|
||
|
|
/* Bound degree based on Laplace expansion */
|
||
|
|
len = n*(l - 1) + 1;
|
||
|
|
|
||
|
|
/* Not enough points to interpolate */
|
||
|
|
if (len > nmod_poly_mat_modulus(A))
|
||
|
|
{
|
||
|
|
nmod_poly_mat_det_fflu(det, A);
|
||
|
|
return;
|
||
|
|
}
|
||
|
|
|
||
|
|
x = _nmod_vec_init(len);
|
||
|
|
d = _nmod_vec_init(len);
|
||
|
|
nmod_mat_init(X, n, n, nmod_poly_mat_modulus(A));
|
||
|
|
|
||
|
|
for (i = 0; i < len; i++)
|
||
|
|
{
|
||
|
|
x[i] = i;
|
||
|
|
nmod_poly_mat_evaluate_nmod(X, A, x[i]);
|
||
|
|
d[i] = nmod_mat_det(X);
|
||
|
|
}
|
||
|
|
|
||
|
|
nmod_poly_interpolate_nmod_vec(det, x, d, len);
|
||
|
|
|
||
|
|
_nmod_vec_clear(x);
|
||
|
|
_nmod_vec_clear(d);
|
||
|
|
nmod_mat_clear(X);
|
||
|
|
}
|